Organic carbon release, denitrification performance and microbial community of solid-phase denitrification reactors using the blends of agricultural wastes and artificial polymers for the treatment of mariculture wastewater

Enhanced Biological Nitrate Removal from Groundwater in Humid Tropical Regions Using Corn Cob-Based Permeable Reactive Barriers: A Case Study from Panama

“…Bands below 1000 cm −1 in the "fingerprint region" are associated with unsaturated bonds [72,76]. The wavenumbers close to 1049 cm −1 and 1047 cm −1 , observed in the fresh corn cob and the samples at varying nitrate concentrations and in the column test samples, respectively, are attributed to the stretching vibration functional group of C-O bonds in cellulose.…”

“…In Figure 11b, a peak at 1641 cm −1 can be observed, which can be assigned to the bending of CO groups in proteins [75]. The absorption peak at 1733 cm −1 belongs to the C=O stretching functional group [35], characteristic of aldehydes and carboxyl compounds typically found in biomasses with hemicellulose [40] and lignin [76] content. On the other hand, the peaks at 2921 cm −1 (Figure 11a) and 2933 cm −1 (Figure 11b) are in the C-H bond, common in cellulose.…”

“…The cob and column samples exhibit a strong intensity of these frequencies. In the case of the column samples; this could be attributed to the binding of water to the surface of the biomass following the biological experiment [76], suggesting the presence of more hydrophilic functional groups. Conversely, the samples of cob 20, cob 30, cob 70, and cob 115 show weak peaks at 2921 cm −1 , which belong to the O-H group.…”

“…Conversely, the samples of cob 20, cob 30, cob 70, and cob 115 show weak peaks at 2921 cm −1 , which belong to the O-H group. This could indicate that these samples have a weaker water binding capacity than the column samples and the untreated cob [76].…”

“…The diminished peak at 869 cm −1 after treatment suggests that many of the ring structures in the column samples were disrupted during the experiment[35]. Additionally, a peak close to 871 cm −1 could indicate the presence of polysaccharides[75].Bands below 1000 cm −1 in the "fingerprint region" are associated with unsaturated bonds[72,76]. The wavenumbers close to 1049 cm −1 and 1047 cm −1 , observed in the fresh corn cob and the samples at varying nitrate concentrations and in the column test…”